Wallinga et al. [1]} showed that school-aged children and young adults are more likely to get infected and contribute most to the spread of infection due to their high number of contacts. The 65 study participants of Edmunds et al. [2]} showed that the mean age of contacts increased with the age of participants, and older participants (\(\ge 40\)  years) had more contacts with older adults and a larger variability in the age of their contacts than younger participants (\(<40\)  years).
